How to create spiral in blender?
Here is a node tree to create a spiral from a Wave texture. It takes generated texture coordinates, splits them, and converts them to polar coordinates with the atan2 node and the Pythagorean theorem. It then adds the coordinates together so that the texture rotates as you get away from the center.

The Greater Than node acts as a threshold, to have a clear separation between black and white.

To change the direction and rotation speed, you can tweak the light grey Multiply node in the center. Value is the rotation speed; sign is the direction.